Pioneers in Tech: Margaret Hamilton’s moonshot

NASA estimates 400,000 individuals contributed to Neil Armstrong and Buzz Aldrin’s ability to land on the moon on July 20, 1969. One of them was Margaret Hamilton, a 32-year-old software engineer working at MIT. Hamilton developed the software system that let Mission Control, Armstrong, and Aldrin know that it was safe to proceed with their mission, even though the Eagle lunar module’s computers were flashing warning messages.

Born Aug. 17, 1936, in Indiana, Hamilton was a former high school teacher who had moved to Cambridge, Massachusetts, with her husband so he could attend Harvard Law. The math major took a job in programming at MIT, working on the first U.S. air defense system, the Semi-Automatic Ground Environment (SAGE) project. When Hamilton heard MIT was seeking programmers to help send a man to the moon, she was intrigued, and she was the first programmer hired for the Apollo project.

Hamilton’s approach to her work was this: “Part is realized as software, part is peopleware, part is hardware.” When her young daughter pushed a simulator button that could make a system crash, Hamilton realized an astronaut could make the same mistake—and suggested programming to account for the possibility. The idea was met with derision until astronaut Jim Lovell pressed the same button as Hamilton’s daughter during Apollo 8.

Margaret Hamilton helps save the moon landing

During Apollo 11, just as Eagle neared the moon’s surface, warning lights began to go off. Mission Control could have aborted the mission then and there—but NASA had confidence in Hamilton’s software, which programmed the computer to ignore low-priority tasks in times of trouble and focus on the critical. As everyone knows, Armstrong and Aldrin landed safely.

Hamilton began calling her work “software engineering,” and the term stuck. For her efforts, President Barack Obama awarded her the nation’s highest civilian honor, the Presidential Medal of Freedom, in 2016. LEGO also featured her in its Women of NASA set.